Method of making insoles



Feb. 26, 1952 P. DROUKAS 2,587,446

` METHOD 0F MAKING INSOLES Filed Aug. 25, 1950 555// f/vsauf 67mm/ ,Z2/sour j ff / wa BA rf/ Patented Feb. 26, 1952 UNITED STATES PATENT OFFICE METHOD .0F MAKING IN vSOLES.

Peter Droukas,V Brockton, Masas.

Application August 25, 195,0, Serial No. 181,485

lClaim. l

This inventionrelates to a method of making` insoles and more especially to a method of treatiner leather which is otherwise unsuitable for insole purposes so that it is vamenable to insole use.

In the past,'those parts of a cowhide commonly known as benda that is to say the central portion of the hide along the opposite sides of the backbone, have usually been reserved for the manufacture of heavy outer soies. This part of the hide is very firm and dense and has high wear-resistant qualities, and for this reason `the price for this part of the hide has usually been much higher than the other parts, that is to rsay the shoulders, flanks and belly, the latter having usually been used in making in soles for shoes. Recently, because of the leather substitutes being employed for shoe soles, the demand for bends has progressively decreased until at the present time the cost of this material has dropped very substantially. in spite of the drop in the cost and the fact vthat this material has become almost a drug on the market, it has not heretofore been considered acceptable as a material for making insoles for the reason that the flesh of the bend is of such a fibrous character that it is not suitable for the channeling operation required to provide the insole with a stitch groove; furthermore, the bend is too thick to be acceptable for use as an insole. v

The principal objects of this invention are to make suitable insoles having ycharacteristics such as pliability and softness, and yet a firmness at least equivalent to those produced from convenitionaimaterials such as shoulders, flanks, etc. from the firm, dense leather taken from the backbone area of the hide, in an economical manner. As herein illustrated, the method of securing a pliable material suitable for insole use, comprises removing a split from the bend material of suitable thickness, treating it to loosen its constituent fiber stock, buing the split surface, applying a surface coating thereto and then exposing the coating to infra-red radiations to bake it. The loosening or pliabilizing step in the process includes dipping the split in a fluid bath of oil and Water, the oil used being cod oil, removing the split from the bath, piling a number of the splits for mulling, air drying the splits, and then bufng and coating them. It is desirable in the finishing operation following bu'ing, coating and drying, to rebuif the coated surface to remove superfluous coating, rebake it, and then to remove the loose fiber stock from the flesh side of the split and compact the whole by rolling. It is Within the scope of ythe invention to subject the split to the foregoing treatment as such and to dink the ,soles therefrom at the end of the process; to cut the lsoles from the hide, split them and then treat the split as indicated above, or to cut the soles from the hide at any time during the processing which seems judicious from the standpoint of economy and continuity.

The invention will now be described in greater detail with reference .to the accompanying drawings which illustrate the steps of the process from the initial stage in which flesh splits are taken from the hide to the nal stage in which the splits or insoles are compacted and ready .for packaging.

Referring to the drawings, and starting at the top of the sheet, a conventional tanned hidel is shown as having along the back portion thereof areas I2 which lie close to the opposite sidesof rthe backbone, represented by the'line I4 which are of a Vrather dense, rrn character andvheretofore have been used for making 'heavy outsoles. These areas are commonly known as bends and in accordance with the present method of preparing the hide in these areas for use in making insoles, that portion of the hide Vis removed from the remainder and is split or soles out therefromV are split to provide a grain split and flesh .split or grain split sole and flesh split sole. The split having the grain surface is used without modification for slipperbottoms. The esh sole or Aflesh split are treated to pliabilize them for insole use as follows. `Since rit vis immaterial' whether the leather is treated as a split from which vseveral insoles may be cut or in the form of a single ,split sole, in thefollowing description the vvterm split Vwill be used to denote either one.

The split is rst dipped into a fluid bath consisting of a mixture of oil and water* Preferably sulphonated cod oil is used which is dispersible in water, forming an emulsion-like mixture. A mixture of one part cod oil to ten parts of Water has been found to be satisfactory. The splits are soaked for a period of approximately one hour, whereupon they are removed and stacked for mulling for a period of approximatey ly 24 hours, during which time the oil and water softening, it is also Within the scope of this invention to use any of the commonly available sulphonated oils such as castol oil and neatsfoot oil.

Following grading, the splits are subjected successively to a buing operation, a coating operation and a drying or baking operation. A conventional buiiing wheel may be used and is applied to the split surface of the splits to make it smooth for receiving a finish coating of suitable composition, many of which are available for bottom finish. The latter is sprayed onto the surface of the split, although it is to be understood that it can be applied in any other suitable manner, such as by rolls, svvabs, and/or partial dipping. The drying operation is carried out by means of a battery of infra-red lamps which subject the coating to infra-red radiations, baking it on the surface.

As illustrated by Way of example, the bufng, coating and baking operations are carried out While the split is supported on an endless conveyor, it being noted that the split may be turned by hand between operations to expose either or both sides to one or more of the operations as may be desired.

The splits may then be run through a fleshing machine to remove the loose fiber at the iiesh side and finally rolled to compact them or further treated on a continuation of the endless belt referred to above or upon an independent traveling belt successively to a repetition of the foregoing treatment, that is a second buffing operation, a second spray coating operation and a second drying or baking operation. The second buffing operation is for the purpose of removing surplus coating applied during the first application of coating so as to leave little more than coating material in the pores of the surface. The

second coating operation and drying operation are identical with those described heretofore.v

While as illustrated herein, a second belt is used for the second series of steps, it is obvious that only one endless belt is necessary since the splits discharged from the end of the rst belt could be replaced on this belt for treatment by the same instrumentalities; moreover, the several steps may be carried out independently, without thev assistance of a conveyor if preferred.

Following the first or second baking operation the split is reversed in position and its uncoated flesh surface is subjected to the action of a iieshing machine to remove loose material from the flesh side and it is then passed through .a rolling machine where it is rolled and compacted. Usiually .the fleshing and rolling would follow the second baking operation when the split is treated splits or soles, are then sorted and tied in bundles and are ready for use.

The insole element thus treated may readily be channeled on its flesh side to provide stitch grooves the same as though it was made from the looser bered stock coming from the cheaper parts of the cowhide and will retain the sewing stitches and other fastening elements just as well as insoles made according to previous methods. The resulting insole material is very flexible. strong and because of the fact that the bends" may be secured at such a low price insoles made therefrom may be produced at a very substantial price saving.

It should be understood that the present disclosure is for the purpose of illustration onlyand that this invention includes all modifications and equivalents which fall within the scope of' the appended claim. 1

I claim:

The method of preparing flesh splits suitable for insoles from fully tanned bend leather which is very iirm, dense and too stiff and thick for use as an insole material and whose flesh side is of a fibrous character such that it is not normally suitable, when split from the grain side of the leather, for use in making an insole, said method comprising as steps splitting the fully tanned bend leather to form a grain split useful, Without further tanning, for making a light-weight outer sole, and a iiesh split of appropriate thickness for use in making an insole and, without further tanning, soaking the esh split in a fluid solution of water and sulfonated cod oil in the proportion of 1 part of oil to 10 parts of water, removing the split from the soaking bath, stacking a plurality of said splits and permitting them to mull, airdrying the individual splits, buffing the split surface of each split, applying a iinish coating thereto, baking the nish coating, removing loose iiber from the uncoated surface of the split after baking it, and rolling the split to compact it.

PETER DROUKAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 267,572 Mundell et al Nov. 14, 1882 534,146 Frank Feb. 12,1895

OTHER REFERENCES Tanning Processes August C. Orthmann, Hide and Leather Publishing Co., 1945,l pp. 231- 

